Here is a tutorial to describe how to revoke (remove) apps from your account.
Step 1
First of all, you need to know which app (application) you have connected to your account.
Visit https://steemd.com/@your-username or https://v2.steemconnect.com/apps/authorized (i'll use steemd.com), scroll down and check the column in your left hand. You will see something like this. Copy the name of the app that you want to revoke.
Step 2
Visit https://v2.steemconnect.com/revoke/@app-name e.g. busy.app and you should look something like this. Click continue.
Step 3
Login with your details.
Step 4
You will see this confirmation text.